In the related art, for example, in order to maintain a session that is established between a terminal and a server, a session maintenance operation of transmitting and receiving a session maintenance signal between the terminal and the server is known. In some cases, the session maintenance operation is performed in each of multiple protocols within the terminals.
Furthermore, a technology is known in which a session maintenance signal is not transmitted on a radio channel in such a manner that a reduction in power consumption and a radio resource on the terminal side are optimized (for instance, refer to Japanese Laid-open Patent Publication No. 2013-211747 that will be described below). Furthermore, a technology is known in which communication with an external device is performed using a session that is already established in such a manner that a network resource is efficiently used (for example, refer to Japanese Laid-open Patent Publication No. 2013-118663 that will be described below). Furthermore, a technology is known in which a timer is used for a connection using a radio resource (for example, refer to Japanese Laid-open Patent Publication No. 2013-046274 that will be described below).